Humidification

Humidity may need controlling in almost every type of building, both for comfort and health and for the building's contents and processes. In many cases this is undertaken using well-established natural mechanisms, but there are often circumstances where the total-life cost of the building would benefit from active humidification control.Cold outdoor air will characteristically have a low moisture content, as will outdoor air in hot arid climates, and will frequently require humidification to provide comfortable and productive internal conditions. Conversely, warm outdoor air (other than in arid climates) will characteristically have a high moisture content and may need to be dehumidified to meet comfort conditions. It is important that comfort air-conditioning systems should not operate both cooling and humidifying equipment at the same time as this can be hugely wasteful; it is normally avoided through proper design and control. This guide will specifically consider the means of increasing the humidity of air to ensure that it does not fall below appropriate levels – a process known as humidification.This guide will explain: — what 'humidity' means— the reasons for controlling the humidity levels in the built environment— the processes that make humidifiers work— the main types of humidifiers used in buildings— how to determine the humidification load— the energy used when humidifying— the selection of humidifiers— the operational needs of humidifiers.